Screen going black every 32 seconds

Question

I have Ubuntu 17.04 running on a Toshiba Portege Z30-C Z30-C. Since two days ago I have a problem of screen blacking out after 32 seconds of inactivity. If the audio is playing, it keeps on playig but the screen goes black. The command xset -q produces this output:

Keyboard Control:
  auto repeat:  on    key click percent:  0    LED mask:  00000000
  XKB indicators:
    00: Caps Lock:   off    01: Num Lock:    off    02: Scroll Lock: off
    03: Compose:     off    04: Kana:        off    05: Sleep:       off
    06: Suspend:     off    07: Mute:        off    08: Misc:        off
    09: Mail:        off    10: Charging:    off    11: Shift Lock:  off
    12: Group 2:     off    13: Mouse Keys:  off
  auto repeat delay:  600    repeat rate:  25
  auto repeating keys:  00ffffffdffffbbf
                        fadfffefffedffff
                        9fffffffffffffff
                        fff7ffffffffffff
  bell percent:  50    bell pitch:  400    bell duration:  100
Pointer Control:
  acceleration:  20/10    threshold:  4
Screen Saver:
  prefer blanking:  yes    allow exposures:  yes
  timeout:  0    cycle:  600
Colors:
  default colormap:  0x20    BlackPixel:  0x0    WhitePixel:  0xffffff
Font Path:
  /usr/share/fonts/X11/misc,/usr/share/fonts/X11/Type1,built-ins
DPMS (Energy Star):
  Standby: 0    Suspend: 0    Off: 0
  DPMS is Disabled

so the culprit is not DPMS as suggested here: ubuntu 16.04 LTS 64bit - screen goes black every 15 seconds.

Can anyone help with this annoying problem?

Edit: Thanks for interest Pilot6 ! The lspci -k | grep -EA3 'VGA|3D|Display' command yields:

00:02.0 VGA compatible controller: Intel Corporation HD Graphics 520 (rev 07)
        Subsystem: Toshiba America Info Systems HD Graphics 520
        Kernel driver in use: i915
        Kernel modules: i915